Stress relief MEMS structure and package

Abstract

Stress relief structures and methods that can be applied to MEMS sensors requiring a hermetic seal and that can be simply manufactured are disclosed. The system includes a sensor having a first surface and a second surface, the second surface being disposed away from the first surface, the second surface also being disposed away from a package surface and located between the first surface and the package surface, a number of support members, each support member extending from the second surface to the package surface, the support members being disposed on and operatively connected to only a portion of the second surface. The support member are configured to reduce stress produced by package-sensor interaction.

Description

FIELD OF THE INVENTION[0001]This invention relates generally to MEMS sensors, and, more particularly, to structures for stress relief in MEMS sensors.BACKGROUND[0002]Micro-Electrical-Mechanical-Systems (MEMS) such as sensors can be widely used in applications such as automotive, household appliance, building ventilation, and in general industrial applications to sense a physical condition such as pressure, temperature, or acceleration, and to provide an electrical signal representative of the sensed physical condition.[0003]Most sensors are sensitive to stress or strain of their physical structure in addition to being sensitive to the measurand of interest. Such stresses can be internally generated by virtue of the sensor structure itself, or can be externally generated by the sensor's enclosure, or packaging. Package stresses, such as thermal stress, can affect the output of a MEMS sensor. One example of package-sensor interaction stresses are stresses caused by the mismatch in the...

AI Technical Summary

Benefits of technology

The patent text describes a system and method for reducing stress between a package and a sensor during the assembly process. The system includes a sensor with a first surface and a second surface that is located between the first surface and the package surface. The method includes etching into a surface of a component of the sensor structure to form the second surface and support structures on the second surface. These support structures are connected to only a portion of the second surface and are designed to reduce stress caused by the interaction between the package and the sensor. The technical effect of this invention is to minimize damage to the sensor during assembly and reduce the risk of malfunction caused by high stress levels.

Problems solved by technology

The conventional methods are not suitable for some MEMS pressure sensor packages.

For example, the use of flexible support beams requires extra stress relief support structure, which is not hermetic and cannot withstand high applied pressure.

Other conventional methods require extra parts or result in a high cost due to complex manufacturing requirements.

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